Washington: Vitamin D, once associated with rickets and osteoporosis, is now recognised as a key player in contributing to overall health, according to the latest research.

Anthony Norman, expert on vitamin D from University of California Riverside (UCR), identified its potential for contribution to good health in secretion and regulation of insulin by the pancreas, heart and blood pressure regulation, muscle strength and brain activity.

Vitamin D deficiency can impact 36 organs like bone marrow, breast, colon, intestine, kidney, lung, prostate, retina, skin, stomach and the uterus. Already, vitamin D deficiency is associated with muscle strength decrease, high risk for falls, and increased risk for colorectal, prostate and breast and other major cancers.

"It is becoming increasingly clear to researchers in the field that vitamin D is strongly linked to several diseases," said Norman, a distinguished professor emeritus of biochemistry and of biomedical sciences who has worked on vitamin D for more than 45 years, according to a release of UCR.

Vitamin D is synthesised in the body in a series of steps. First, sunlight's ultraviolet rays act on a precursor compound in skin. When skin is exposed to sunlight, a sterol present in dermal tissue is converted to vitamin D, which, in turn, is metabolized in the liver and kidneys to form a hormone. It was Norman's laboratory that discovered, in 1967, that vitamin D is converted into a steroid hormone by the body.

The recommended daily intake of vitamin D is 200 international units (IU) for people up to 50 years old. The recommended daily intake of vitamin D is 400 IU for people 51 to 70 years old and 600 IU for people over 70 years old. Norman's recommendation for all adults is to have an average daily intake of at least 2,000 IU.

While deficiency of vitamin D impacts health negatively, ingestion of extremely high doses of vitamin D can cause hypercalcemia, a condition in which the blood's calcium level is above normal.

The paper was published in the August issue of the American Journal of Clinical Nutrition. IANS